VW Pickup/Caddy Rear Suspension

The Caddy has a rather unique (to VWs anyway) suspension. MacPherson
struts up front and a leaf spring over axle rear suspension. The main
leaf is approx. 52" long, with a long second leaf and a shorter
overload type leaf on the bottom of the pack. A conventional spring
shackle is in back to accommodate the flexing of the spring. Two shock
absorbers mount between tabs on the tube axle and brackets on the bed
sub frame.

After getting tired of the rear end bottoming out over bumps, I first
picked up a 1500lb.-rated helper spring to attach to the rear leaf
spring. This helper attaches to half the spring, clamping to it near
the spring perch and then it lifts under the stock leaves.

After running the helper spring for a number of years, I decided a full
length spring leaf might work better. So, armed with an ample supply of
left-over leaves from my Toyota, I found an ideal add-a-leaf for the
pickup was the 3rd or 4th leaf from the front spring pack, of an 1985
or earlier Toyota truck. To install it, I jacked up the rear end,
removed the lower shock mount, pulled the nuts off the u-bolts and
removed the spring center bolt. I slid the Toyota leaf in between the
2nd and 3rd VW leaves (I applied a good helping of axle grease to the
leaves while they were apart), spring clamp forward (spread open to fit
the slightly wider VW springs) and installed a new, longer spring
center bolt. One thing to watch for is the VW tube axle perch has a
hole drilled into the axle for the center bolt head. If not supported
the bolt can (and will) drop down inside the axle. Reassemble the
u-bolts and shock and you'll not enjoy a much firmer, yet not harsh
ride. By lifting the main leaves off of the overload leaf, your ride
will be smoother than stock. I found the 3rd Toyota leaf restored equal
front ad rear ride heights.

An advantage of the stiffer rear springs is that the lack of a rear
sway bar is minimized. Until I stiffened the springs, I was looking for
a sway bar that could be adapted to the Caddy, but I don't think it is
necessary now.

Spray the shock and spring u-bolt nuts with a shot of penetrating oil a
few days before starting the swap

If interested, measure the distance to the rear wheel wells to get a
"before" measurement

Jack up the rear end and support the bumper on jack stands

Remove the wheels to gain access to the springs

Remove the lower shock retaining bolts

Loosen the u-bolt nuts on both sides

Use a jack to support the axle if desired, its not really that heavy
though

If you have less that 1/4" of thread protruding from the u-bolts,
you may need longer ones (see picture #3 above)

Remove the nuts from the u-bolts on one side and take off the plate and
u-bolts

Use a vice-grip to hold the bottom of the center pin bolt and remove
the nut on top

Some penetrating oil applied to the center bolt may be a good idea

If you have less than 1/4" of thread protruding from the center
bolt, you will need a longer one

I've found that a 3/8-NF allen head screw/bolts works great for this,
the new spring pack is just over 1" thick, so a 1-1/4 to
1-1/2" long bolt is fine.

Alternately, a hex head bolt will work, just knock off the corners of
the head to fit the hole in the spring perch

Otherwise, I can supply you a longer center bolt with the leaf springs
if desired

Same story on the u-bolts, I've heard you can order new u-bolts at any
NAPA auto parts store, just give them the diameter of the bolt, the
diameter of the axle and the desired length of the "U" to get
new ones; on my truck they measure:

Approx. 3/8 x 2-3/4 x 5", so another 1/2" or so added to the
5" length would be just the ticket

WORD TO THE WISE - don't take the vice grips off until
you can pull the center bolt free, the hole in the spring perch is open
below and the center bolt can (and will:) fall down
inside the axle tube and you'll have a rattle that will last the life
of the vehicle, trust me!

Reinstall the lower shock bolt and wheel, do the other side and you are
done

Its a good idea to re-check the fasteners in 100-500 miles

If interested, measure the distance to the rear wheel wells to get a
"after" measurement

I've seen anywhere from 1-2" of lift, depending on the conditions
of your old springs and the load in the vehicle

These add-a-leaves are good for everyday driving and occasional
heavy loads. We usually have a few sets of these leaves available. We
disassemble the spring pack, sand the rust and dirt off the leaves,
then apply some paint. Folks have reported anywhere from 1-2" of
lift, depending on how bad your current springs have sagged and how
much load you carry. In only one case has it been necessary to replace
the stock u-bolts, however, longer center bolts are almost always
required.

I used to run a set of 1500# overload springs. If you routinely carry
heavy loads, these are ideal. The ones I used are similar to the
following JC
Whitney 87ZX5964Y. These are a lot easier to install than the full
length springs, too.

When I purchased my '82 Caddy, it had a set of Rancho add-a-leaf
springs that were installed by the pervious owner (see image #1 below).
He apparently hauled a lot of hay and horse tack as part of his
business. Anyway, I found those springs way too stiff for the Caddy,
even with a shell on the back. Also, he had installed some KYB shocks
that were about 2" longer than the proper ones and without the
stiff AAL, the shocks yould bottom out fairly easily. I decided to play
around a bit with the rear springs and shocks to improve both the load
capacity and ride.

1:
2:
3:

First thing I did was to get some longer u-bolts, I used a 1/2"
Rancho u-bolt, and redrilled the spring plate for the larger bolts. I
then fabricated some new leaves to replace the lower overload leaf (see
image #2 above). I staggered the length of the leaves for a nice
progressive rate and bolted them up into a 5-leaf pack (see image #3
above). For the shocks, I fabricated a bracket to move the top end of
the shock farther away from the axle (see image #4 below). This places
the shock at a shallower angle which both allows the longer shock to
fit without bottoming and it also reduces the damping rate a bit, which
is nice since I find the KYBs are a bit stiff.

4:
5:

So, how does the new setup work? Great, my first test was to drop a
1200 lb. milling machine in the bed (see image #5 above). No problems
at all as I hauled the mill about 15 miles to my garage. I found the
rear end settled about 1.5" under the load (approx 400#/in per
spring) and I still had about 2" of clearance at the bumpstop.
Surprisingly the ride was quite nice with that weight, no wallowing, it
was smooth and solid. I get about 1" of lift over my front end
(which itself may be 1/2" - 1" higher than stock). Ride is
very nice unloaded, it greatly reduced the "pitching" I used
to get on uneven pavement, where the rear end would pitch the front end
down as it went over bumps.

Also, you can see the rear sway bar I had previously installed in image
#4, above. It was bought used, unknown mfg. Along with the front
Neuspeed bar, I get very little body roll, even with my tall
"Caddy Shack" in place. Handling is quite nice, despite the
skinny 13" all season tires I run.

I had the stock rear shocks on my 1981 pickup replaced with KYB Gas-A-Just shocks in 1992 (model
KG5449). They held up very well and seem to be as firm as when new when
the pickup was totaled in early 2000. The shocks have 10mm (3/8")
diameter mounting bolts top and bottom and measure 10-7/8"
collapsed and 17" fully extended from center to center at the
mounting holes. I find that the 17" length is slightly short and
the spring wants to drop a fraction of an inch at full droop. With my
helper spring, I find the shock is compressed 2" (of its 6"
travel) at rest and there is about 4" of axle travel to the bump
stop. So, it appears this is a decent length shock for this application.

My 1982 pickup had a set of KYB KG4012 shocks installed when I bought
it. They are about 13.5" compressed and approx. 21.5"
extended. As such I found they tended to bottom out easily with any
load in the bed. To correct this I moved the upper shock mounts out
about 4" from their stock location to allow them to fit without
bottoming. These shocks would be a good addition to a 2" to
3" lift block setup, since they have the extra length needed for
that application.

There are some interesting Rancho shock applications that might be
adapted to fit the Caddy. From my shock
selection table, I see:

Model RS9006 18.31"/ 11.66" with 5/8" diameter mounting
loops

Several other RS9000 models are of similar length. The RS9000 shock is
adjustable and can be fitted with an in-cab remote adjuster too. The
RS5000 models come in similar lengths but are fixed rate and typically
are very stiff, equivalent to the 9000 at a 4 or 5 setting.

Another interesting rear suspension option is to use Gabriel
Air-adjustable Hyjacker shocks. While Gabriel lists no VW pickup
application, evidently, the VW Beetle rear shocks are almost an exact
fit. The air-over-oil shocks are supposed to add up to 1000lbs. of load
carrying capacity to the axle, depending on air pressure. Couple that
with an electric air compressor and you could have an in-the-cab ride
height adjustment, way cool!

However, after years of enjoying the ride of the front Bilstein HD
struts, I decided to set about fitting a set of rear Bilstein shocks.
Unfortunately, Bilstein does not list a rear shock for the pickup/Caddy
model, unlike the fronts, which are the same as the Rabbits use. But it
turns out, the rear shocks for a Volvo 760 (p/n: FA-B46-0296-H2) are
just about the right compressed and extended length and one would
imagine the gross vehicle weights are comparable, so that is a good
starting point.

A: A pair of Volvo shocs

B: Changes to bottom mount

C: Changes to upper mount

D: Closeup of upper mount

So in picture A, above, are the shocks as received. The only issue is
the mounting eyes on the shocks, the supplied sleeves are too wide to
fit in the rear shock mounts on the pickup. Also the sleeves have too
small a hole to accomodate the VW shock mounting bolts. At first I
tried to trim the sleeves shorter and then drill them out, but that
proved futile. So the easiest way to address this is to press out the
Volvo sleeves and fabricate a new sleeves to replace them. I used some
thin wall aluminum tubing sized to fit the ID of the rubber eye bushing
and cut them to length to fit the VW shock mounting brackets and
drilled the ID of the sleeve to fit the 10mm VW shock bolts. Once those
were ready, I found I just needed to grind a small bit of rubber of the
face of the upper bushing to allow it to fit into the tight slot under
the bed.

The sleeves are cut to match the 30mm thickness of the Bilstein shock
bushings, but sometimes the shock mounts on the pickup may have been
bent inward over the years, thus the need to file/grind down the width
of the sleeve/bushing to make it fit.

After all, it is always easier to remove a little material, if needed,
than to put more back on.

Also, the shocks are a tiny bit too short to install with the axle
hanging all the way down, so you need to raise the axle slightly to get
the lower bolts in. Actually, this is a good thing, as the gas shocks
will fully extend quite fast and are very hard to compress by hand, so
if they were a little too long (instead of too short), installation
would be a bear, as you would need to find a way to compress the shocks
by hand and with the internal high pressure gas, that is very hard to
do.

And the finished product:

E: Rear Bilstein shocks!

And how is the ride?

One word: Wonderful!

Very nice, and very well controlled, loaded or unloaded, there is no
change. And with the front and rear shocks matched, there is no longer
the pictching felt on stretches of freeway with the uneven concrete
sections. With the old KYBs, the pickup used to pitch up and down over
those sections of road, almost getting into a resonance at the right
speed. Now, it just follows the road. Note that the ride is firm, it is
not a soft cushy Cadillac type ride. It is not harsh, though, just
firm. I am very happy with the results.

If interested in installing these shocks on your pickup, Missing LinkZ
can supply a set of sleeves for a cost of US$25.00 (US shipping
included). And if you would like a set of Bilstein shocks, ready to
bolt in, that can be arranged. It does take a while to source/modify
the shocks and they do run around US$125.00/ea., ((US$250.00 for the
pair) so be advised. US shipping typically runs from $25-$30 depending
on destination.

If you want to modify your own shocks, we can also supply the 4
VW-sized bushing sleeves that you can use to replace the Volvo-sized
sleeves in your shocks. Cost for the sleeves is $25.00 plus shipping ($4.00
for US first class or $8.00 for US Priority or US$24 .00 for
international Priority mail). To install, you need to press the rubber
bushings and sleeves out of the shock eyes (can be done with a long
bolt, nut and deep well socket), then press the Volvo sleeve out of the
bushing, then press/hammer the rubber bushing back into the shock eye
and finally insert the VW sleeve into the bushing.